Chicago Law School in 2013. He is a member of the American Bar Association, the New York City Bar Association (Chair, Communications Law Committee, 1986–89), and the American Judicature Society. He is a Fellow of the American Bar Foundation. Sack is an adviser, American Law Institute's Restatement Third of Torts, Defamation and Privacy, 2019– ; an adviser to the "Global Media Freedom Initiative's High-Level Panel of Legal Experts" convened at the request of the UK and Canadian governments, 2019– ; and a member of the editorial board of the Journal of Free Speech Law, 2021– . Publications • Sack on Defamation: Libel, Slander and Related Problems (5th ed. 2017) (updated annually) • New York Times Co. v. Sullivan — 50-Year Afterwords, 66 Ala. L. Rev. 273 (2014) • "Protection of Opinion Under the First Amendment: Reflections on Alfred Hill, 'Defamation and Privacy Under the First Amendment,'" 100 Colum. L. Rev. 294 (2000) • Advertising and Commercial Speech: A First Amendment Guide (1999) (co-author) • "Hearing Myself Think: Some Thoughts on Legal Prose," 4 Scribbs Journal of Legal Writing 93 (1993) • "Reflections on the Wrong Question: Special Constitutional Privilege for the Institutional Press," 7 Hofstra L. Rev. 629 (1979) Notable opinions Doe v. Trump Corporation, 6 F.4th 400 (2d Cir. 2021): Sack, writing for the panel, held that defendants Trump Corporation, Donald J. Trump, and members of his family were not entitled to have the district court enforce an arbitration agreement in a suit for unfair business practices and deceptive statements regarding a multi-level marketing company. United States v. Ceasar, 10 F.4th 66 (2d Cir. 2021): Sack, writing for the panel, held that a sentence of 46 months' imprisonment for a defendant who pled guilty to providing material support to the Islamic State of Iraq and Syria was shockingly low and thus substantively unreasonable, when the defendant had already exhibited recidivist behavior while awaiting sentencing and faced a Guidelines range of 360 to 600 months' imprisonment. Badilla v. Midwest Air Traffic Control Service, Inc., 8 F.4th 105 (2d Cir. 2021): Sack and Lohier, writing for the panel, held that state-law wrongful death claims against an air traffic controller for negligently causing a civilian flight to crash into a mountain near Kabul Afghanistan International Airport were not preempted by the combatant activities exception to the Federal Tort Claims Act, and that factual disputes remained regarding breach of duty of care and